Osteogenesis imperfecta (Ol) is a clinically and genetically heterogeneous disorder of bone. The phenotypes range from lethal in the perinatal period to an extremely mild presentation with rare fractures. [unreadable] [unreadable] The majority of affected individuals have a mutation in either of the two type I collagen genes, COL1A1 and COL1A2, but about 10-15% likely have mutations in other genes, none of which have yet been identified or characterized. [unreadable] [unreadable] "New Research Strategies in Osteogenesis Imperfecta" will be held in Chicago, IL on April 26 and 27, 2006. This scientific meeting will bring together approximately 45 investigators to share new scientific data from current Ol research and shape the focus of future research efforts. Just as importantly, it will bring together the clinical directors involved in the Linked Clinical Research Centers (LCRC) project, a cooperative network of research and treatment facilities nationwide designed to increase research opportunities and improve the standard of care for people with Ol. The use of treatment data will be a specific focus of this meeting, particularly the variation between people in their response to Ol treatments. Traditionally, treatment data are presented for populations as means with standard deviation, etc. What this does not do is stratify response and begin to identify people who respond less well and those who respond "too well". Such response heterogeneity is becoming evident to clinicians worldwide, and skeletal toxicity from especially bisphosphonate treatment has been reported. Researchers will discuss their data in terms of factors like intrafamilial variation where we know there is a single mutation, the intrafamilial variation with single mutations, and the stratification of response to bisphosphonates, growth hormone, rodding, and other treatments. Conference sessions will be organized so that participants divide their time between clinical and collaborative issues and research data. The first day will be dedicated to Clinical Management Issues, with sessions to be held on rodding surgery, response to therapies involving bisphosphonates and other drugs, variation in fracture repair in and between families, and rehabilitation. During the second day, participants will focus on research issues during sessions devoted to pathophysiology/cell and bone biology, New Ol genes and determinants of variation, mouse and other animal models, and future strategies. [unreadable] [unreadable] [unreadable] [unreadable]